1. Field of the Invention
The present invention relates to a deposition mask provided with a plurality of opening patterns corresponding to a plurality of thin film patterns to be deposited on a substrate, and more particularly, relates to a deposition mask capable of forming high definition thin film patterns with high positional accuracy, and a method of manufacturing the deposition mask.
2. Description of Related Art
A conventional deposition mask is a metal mask provided with a plurality of penetrating opening patterns corresponding to a plurality of thin film patterns to be deposited on a substrate. The mask is manufactured as follows: a first resist pattern having a plurality of through openings is formed on a metal plate, an etching process is performed through the through openings of the first resist pattern to thereby form a plurality of through holes penetrating through the metal plate, the first resist pattern is removed, a second resist pattern having a plurality of second through openings, each exposing a metal edge portion with a predetermined width around each of the plurality of opening patterns on the metal plate, is formed, an etching process is performed through the second through openings of the second resist pattern, to thereby form: a mask body portion around each of the plurality of through openings; and a peripheral portion, having a thickness greater than that of the mask body portion and positioned around the mask body portion, and then, the second resist pattern is removed (for example, see Japanese Patent Application Laid-open Publication No. 2001-237072).
However, in such a conventional deposition mask, the etching process is performed on the metal plate to form the plurality of penetrating opening patterns in the metal plate, and thus, it is not possible to form a high definition opening pattern with a high level of accuracy. In particular, for example, in a case of a large area deposition mask for an organic EL display panel having a large area in which a length of one side of equal to or greater than several tens of cm, it is not possible to uniformly form a high definition opening pattern over the entire surface of the mask, due to the occurrence of etching unevenness, an increase in an opening area caused by isotropic etching, and the like.